Removing a piston that is stuck in a knucklehead cylinder.

[Paultrehberg]

Have a corridor piston stuck in a knucklehead cylinder. After soaking in penetrate oil for a month and gently hammering on it, it will not move. Do not want to hit it to hard. It is a 41/42 cylinder Any suggestions ????

[Rubone]

What are you using for penetrating oil? Heating and cooling cycles will sometimes aid in breaking the bond. You can also fabricate a pushing tool to bolt onto the top flange (not the base which is more prone to damage) and put pressure on the piston , easy to do with a piece of scrap plate and a large bolt or threaded rod.

[Robert Luland]

Beat that thing out of there. You not saving the piston. Put a 2" pipe down there with a screw on cap and do the lump hammer thing. I mean lay waste to that sucker! Bob L

[T. Cotten]

....I mean lay waste to that sucker! Bob L

Gotta be an AMCA judge to say that!

....Cotten

[Chris Haynes]

Put it in a press and press it out.

[Jerry Wieland]

If it were mine I would break the piston apart and take out the pieces. Knuckle barrels are too had to find to take a chance on breaking the cylinder.

Jerry

[jim d]

I would place the cylinder on a drill press or mill and drill a series of holes through the top of the piston inboard of the cylinder wall to remove the top of the piston. Then I would cut 4 slots from top to bottom with a Dremel or similar tool using a burr. Removing the center top area should relieve some of the internal pressure and give room for things to move when using heat, You can always cut another slot and remove a small piece. If I remember correctly for every .001" of steel lost to rust you gain .009" of rust which adds a lot of pressure to hold things tight. Use a aluminum or brass piece of stock to drive the smaller sections which should shear where you have cut the slots. It will take longer but you will still have your cylinder left in good condition when done. It is not like you have a couple of dozen to do. As Jerry said pieces is the safest way.
Jim D.